Microwave synthesis of graphene/magnetite composite electrode material for symmetric supercapacitor with superior rate performance

Abstract

Pristine Fe₃O₄ and Fe₃O₄–graphene composites were synthesized by using a green and low cost urea-assisted microwave irradiation method and were utilized as electrode materials for symmetric supercapacitor applications. The Fe₃O₄–graphene symmetric cell exhibited a better electrochemical performance than that of the Fe₃O₄ cell with enhanced rate performances. The Fe₃O₄–graphene symmetric cell delivered a stable discharge capacitance, energy and power densities of about 72 F g⁻¹, 9 Wh kg⁻¹ and 3000 W kg⁻¹, respectively at 3.75 A g⁻¹ current density over 100 000 cycles between 0–1 V. The impedance studies also suggested that the Fe₃O₄–graphene symmetric cell showed lower resistance and high conductivity due to the small particle size, large surface area and good interaction between Fe₃O₄ particles and graphene layers.